Fixed gas detectors

Fixed gas detectors are sensors for gaseous substances designed to detect and measure gas concentrations in the air. They measure explosive gases (natural gas, LPG, hydrocarbons, solvents, alcohols), toxic gases, volatile organic compounds (VOCs), asphyxiating gases (lack of oxygen), or freons (refrigerants). Often associated with a gas detection unit to manage the control systems, they ensure daily protection of the installation 24 hours a day, seven days a week.

Fixed gas detectors
  1. Specially designed for applications in boiler rooms or car parks, the OLCT10 fixed gas detector is particularly suitable for monitoring explosive or toxic combustion gases such as CO (carbon monoxide), NO (nitrogen monoxide), and NO2 (nitrogen dioxide). It is a robust, reliable instrument that is very easy to use.

    • Gas detection: explosive gases, CO, NO, NO2
    • Ideal for small boiler rooms and car parks
    • Power supply from 15 to 30 Vdc, linear output 4-20 mA
    • Robust and shock resistant, easy to install and use
    • Excellent value for money
  2. The OLCT10-freons refrigerant leak detector is especially for refrigeration applications in non-classified areas. It uses a semiconductor sensor, and its linear 4-20 mA output allows to connect it to any control panel receiving this type of signal. It is considered an economical and easy way to overcome recharging costs.

    • Detection: R11, R12, R22, R23, R32, R123, R134A, R141B, R143A, R227, R404A, R410A, R407C, R408A, R507, FX56
    • Power supply: 15 to 30 VDC - Linear output 4 to 20 mA (3 wires)
    • Robust and shock-resistant ABS housing
    • Ideal for refrigeration systems, air conditioning, heat pumps, etc.
    • Excellent price/performance ratio
  3. The MGS 410 is a refrigerant gas detector for connection to Bacharach gas detection units via MODBUS. It is a device that can monitor the concentration of many freons and can be integrated into a building management system. It is an excellent value-for-money gas detector that can operate at temperatures down to -40°C.

    • Detection of refrigerant gases
    • Operates in extreme conditions: from -40°C to +50°C
    • Built-in 72 dB audible and visual alarm for refrigeration safety
    • Sealed against dust and strong water jets: IP66
    • Device settings via the MGS-400 mobile application
  4. The Bacharach MGS-450 refrigerant detector can be used as a stand-alone device for detecting refrigerant gases (freons) or connected to a multi-channel control unit. It is a gas detector with alarm relays that can handle a refrigeration unit, a buzzer for alarm reporting, and 4-20 mA and MODBUS outputs for connection to a control system.

    • Detection of many refrigerant gases
    • Temperature-compensated measurements for improved immunity to false alarms
    • 3 relays (low, high, and fault alarms), 4-20 mA output and MODBUS
    • Device set-up on the MGS-400 mobile application
    • Complies with refrigeration standards (ASHRAE 15 & EN 378)
  5. Fixed gas transmitter NB3 dedicated to the monitoring of gas concentrations in safe areas (non-ATEX): Organic acids, Alcohol, Br, C2H2, C2H4, C2H4O, C2H5OH, C2H6, C3H6, C4H10, C5H12, CH2O, CH4, Cl2, ClO2, CO, CO2, H2, H2O2, H2S, HBr, HCl, HCN, HF, Hydrocarbons, N2O, NH3, NO, NO2, O2, O3, PH3, R1234yf, R401A, R404A, R407C, R32, R410A, R12, R22, SiH4, SO2, VOC.

    • 88 pre-calibrated and interchangeable sensors
    • Analog (4-20 mA) and RS485 (DEGA protocol) outputs as standard
    • Several options are available: LCD display, two relay cards, Modbus card
    • Suitable for local fixed gas detection applications with servo control
    • Excellent value for money
  6. NS2 ATEX gas detector dedicated to gas concentrations monitoring in classified areas. Detection: Organic acids, Alcohol, Br2, C2H2, C2H4, C2H4O, C2H5OH, C2H6, C3H6, C4H10, C5H12, CH2O, CH4, Cl2, ClO2, CO, CO2, H2, H2O2, H2S, HBr, HCl, HCN, HF, Hydrocarbons, N2O, NH3, NO, NO2, O2, O3, PH3, R1234yf, R401A, R404A, R407C, R32, R410A, R12, R22, SiH4, SO2, VOC.

    • A wide range of gases detected: 88 sensors available (catalytic, electrochemical, infrared, semiconductor and PID)
    • ATEX zone 2 certification, gas concentrations monitoring in classified areas
    • 4-20 mA & RS485 (DEGA protocol) outputs available with or without LCD display
    • Options available: 3 relay cards, 88 dBA buzzer, Modbus module
    • Datalogger of values over the last 44 days
  7. Specifically designed to detect the most common gas encountered in the light industry or the tertiary sector, the OLCT10N digital gas detector has been developed to be connected in series with Oldham units only. It detects explosive gases (butane, propane, methane, hydrogen), CO, CO2, H2S, NH3, NO, and NO2.

    • RS485 Modbus proprietary digital signal gas detector
    • Available in electrochemical, catalytic, or infrared (CO2) versions
    • IP65 protection rating making it water and dustproof
    • Excellent value for money with substantial wiring savings
    • Automatic calibration without opening the housing
  8. Honeywell's fixed gas detector SensePoint is a cost-effective, high-performance gas transmitter for fixed gas detection installations. It is suitable for operation in potentially explosive atmospheres (ATEX zones) and detects explosive gases (hydrocarbons, solvents, alcohols), toxic gases (Cl2, CO, H2S, NH3, NO2, SO2) and lack of oxygen (N2, O2).

    • ATEX II 2 GD certified (gas and dust) and conforms to EC standards on electromagnetic compatibility
    • Honeywell Surecell high performance electrochemical cells
    • Four-way junction box for quick and easy installation
    • IP65 ingress protection against water and dust
    • Cost-effective and efficient solution with excellent value for money
  9. The B12 ATI is a gas transmitter sensor with a 4-20 mA output, particularly suitable for the detection of exotic gases with a short response time: Alcohols, AsH3, B2H6, Br2, C2H2, C2H4O, CH2O, Cl2, ClO2, CO, COCl2, F2, GeH4, H2, H2O2, H2S, H2Se, HCl, HCN, HF, I2, NH3, NO, NO2, Nox, O2, O3, PH3, SiH4, SO2 & Steam.

    • Fixed gas transmitter sensor with a linear 4-20 mA signal
    • Direct measurement with fast response time
    • NEMA 4X polystyrene enclosure with optional LCD
    • Low power consumption, 12 to 28 VDC power source
    • Minimal and easy maintenance with sensor replacement in seconds
  10. The CTX300 analog gas transmitter is a safe area gas detector with a 4-20 mA linear output for the detection of toxic gases (C2H4O, Cl2, ClO2, CO, COCl2, H2S, HCl, HCN, HF, NH3, NO, NO2, O3, PH3, SiH4, SO2), asphyxiating gases (Ar, CO2, He, O2), organic vapours (VOCs, alcohols, solvents) and refrigerant gases (CFC, HFC, HFO freons).

    • Detection of toxic gases, oxygen, and the main freons
    • 4-20 mA linear analog output, pre-calibrated and plug-in sensors
    • Very robust: insensitive to corrosive agents and high mechanical resistance
    • Optional backlit digital display for local indication of measurements
    • Certification for safe areas only, not ATEX classified
  11. The 3000 Series Toxic Gas and Oxygen Monitor is a low power consumption 2-wire 4-20mA transmitter. All new or retrofit installations can integrate it. It is suitable for use in potentially explosive atmospheres and can be configured non-intrusively using magnets directly through the display's glass window.

    • Gas detection: Cl2, ClO2, CO, ETO, F2, H2S, HCl, HCN, HF, NH3, NO, NO2, O2, O3, PH3, SO2
    • 2-wire loop power supply from 17 VDC to 30 VDC
    • Gas concentration display and parameter setting on an LCD screen
    • Materials: aluminium alloy and epoxy paint (stainless steel optional)
    • Hazardous area certified, UL/c-UL, ATEX, IECEx
  12. The SensePoint XCD is an ATEX gas detector with a display and alarm relay for the detection of explosives (hydrocarbons, solvents, alcohols), toxic (CO, H2S, NO2), or asphyxiating (lack of oxygen or CO2) gases. A three-colour backlit LCD clearly and immediately indicates the status of the device (gas alarms, faults, etc.), even when it is far away.

    • ALL-IN-ONE fixed gas detector for monitoring explosive, toxic, or asphyxiating gases
    • LCD, alarm relay, fault relay, 4-20 mA, and RS485 Modbus outputs
    • 15.5 to 32 VDC power supply, 4-20 mA linear output, and relay output
    • Certifications ATEX Ex II 2 GD Ex d IIC T6 (gas and dust)
    • LM25 aluminium alloy or 316 stainless steel housing with epoxy paint
  13. The SIL2 certified OLCT100 fixed gas detector is available in ATEX versions for explosive gas or intrinsically safe (IS) for toxic gases. With nearly 150 gases listed, this 4-20 mA linear output gas detector is suitable for explosive gases detections (hydrocarbons, solvents, alcohols), toxic, asphyxiating, and refrigerant leaks (freons, HFO, CFC, HFC).

    • Fixed gas detector for explosive gases, hydrocarbons, solvents, toxic gases, freons, VOCs, CO2
    • ATEX & SIL 2 certification for catalytic and infrared versions
    • Epoxy-painted aluminium housing (316L stainless steel optional)
    • Wheatstone bridge or linear 4-20 mA outputs
    • Power supply ranges from 15.5 to 32 VDC depending on the application
  14. The iTrans2 fixed gas detector can provide two sensing points on a single head for maximum flexibility with reduced installation costs. Factory pre-calibrated smart sensors automatically feed parameters into the detector, and a sensor life indicator is displayed immediately after each calibration.

    • Detection of explosive gases, hydrocarbons, solvents, toxic or asphyxiating gases
    • Up to 2 sensing points on one head for maximum flexibility
    • Wide choice of clever sensors (electrochemical, catalytic, or semiconductor)
    • Non-intrusive calibration with magnetic switch
    • MODBUS or HART communication protocol for easy remote operation
  15. The KwikSense is a digital gas transmitter ATEX dedicated to the detection of flammable gases, toxic gases, and volatile organic compounds. It has a digital display, 4-20mA and MODBUS outputs, and alarm relays for the detection of the gases Br2, C2H2, C2H3Cl, C2H6O, C3H8, C4H10O, C6H6, CH3OH, CH3SH, CH4, CH2O, Cl2, CO, CO2, COCl2, CS2, ETO, GPL, H2, H2O2, H2S, HCl, HC, HCN, HF, NH3, NO2, O2, O3, PCl3, PH3, POCl3, SO2 & COV.

    • Digital gas transmitter ATEX for the detection of explosive, toxic and asphyxiating gases, and VOC
    • Digital display and three-color LEDs to indicate detector status
    • Rugged, explosion-proof housing with cast aluminium alloy
    • 4-20mA, MODBUS, and 1 or 3 relay outputs depending on model
    • Excellent value for money with many accessories available
  16. The OLCT80 fixed gas detector is an ATEX gas transmitter with display, alarm relay, 4-20 mA and Modbus RS485 outputs for explosive, toxic, refrigerant, asphyxiating gases, or volatile organic compounds detection. An infrared remote control allows remote configuration without opening the housing.

    • Over 150 pre-calibrated sensors for the detection of explosive, toxic, refrigerant, asphyxiating, or VOC gases
    • LCD display, 2 alarm relays, 1 fault relay, 4-20 mA, Modbus RS485 outputs
    • Configuration and setting in NON-intrusive mode
    • Standards and certification ATEX - II 2 GD, INERIS 03ATEX0240X, compliant with EN50270
    • Available in wireless version with a maximum range of 3km (option)
  17. OLCT710 TP solid-state H2S gas detector is a high-performance gas transmitter that is certified ATEX and SIL2 zones. It has been specifically designed for optimum and reliable operation in the presence of high concentrations of hydrogen sulfide (H2S) when electrochemical cells reach their limits.

    • Semiconductor technology for H2S measurement at high concentrations
    • ATEX & SIL2 certification for use in extreme conditions
    • Suitable for use in high humidity environments (15 to 100% RH) and temperatures ranging from -40°C to +75°C
    • IP66 protection rating, water, and dust proof
    • 4-20 mA analogue output and Modbus RS485
  18. The KwikSense PID VOC detector, ATEX certified, is dedicated to the volatile organic compounds detection. It is an ATEX transmitter with linear 4-20 mA output, alarm relay, and a digital display that can be connected to a control system (safety PLC, gas detection system) or used as a stand-alone control point.

    • VOC detectors with PID technology (10.6 eV photo-ionization lamp) for the detection of volatile organic compounds
    • Digital display and three-colored LEDs to indicate the status of the detector 
    • Rugged, explosion-proof housing with cast aluminium alloy
    • 4-20 mA, MODBUS, and 1 or 3 relay outputs depending on the model
    • Numerous compatible accessories: calibration cap, gas manifold, climate protection, duct mounting kit
  19. Honeywell's SensePoint XCD-RFD and XCD-RTD gas transmitters have been specifically designed for use with remote gas sensors. They can be placed up to 30 meters away from the sensor, allowing information on the presence of toxic or flammable gases to be viewed outside of hard-to-reach areas.

    • Pre-configured and configurable ATEX Ex II 2 GD Ex d IIC T6 (gas and dust) transmitter
    • Up to 30m distance from the sensor to read information beforehand
    • Compatible with catalytic, electrochemical, and infrared gas sensors
    • Backlit display, alarm relay, and 4-20 mA and MODBUS outputs
    • Better events indication with clear colour-coded display (alarms, errors, etc.)
  20. The Universal Gas Transmitter XNX can accept all inputs from various Honeywell Analytics gas sensors. It uses standard 4-20mA or HART wiring and works with several communication protocols (Modbus, Fieldbus, etc.). Its multilingual backlit LCD provides all necessary status information in text, numbers, and icons.

    • Compatible with all Honeywell Analytics local and remote sensors
    • International approvals for use in hazardous areas (ATEX, UL, CSA)
    • Multiple communication protocols (Hart, Modbus, Fieldbus, etc.)
    • Multiple input and output options (linear, digital)
    • Robust aluminium alloy or stainless steel housing
  21. The Satellite XT is an interchangeable cell gas sensor transmitter designed for continuous monitoring of hazardous gas concentrations: AsH3, BBr3, B2H6, BCl3, BF3, Br2, C2H4O, Cl2, ClF3, ClO2, CO, COCl2, F2, GeH4, H2, H2S, H2Se, HBr, HCl, HCN, HF, HMDS, MCF, MMH, N2H4, NH3, NO, NO2, O2, O3, PH3, POCl3, SiCl4, SiHCl3, SO2, TBA, TBP, TDMAT, TEOS, TMB, TMP, UDMH, WF6.

    • Over 50 "rare" toxic gases detectable at low concentration levels
    • Pyrolysis module for fluorinated gases: C4F6, C5F8, CH3F, DCE 1.2, NF3, SF6
    • Interchangeable plug-n-play pre-calibrated cell, easy maintenance
    • Gas extraction pump (optional) for remote sampling or gas removal (up to 50 metres)
    • 4-20mA linear output as standard - 3 single pole relay module configurable as an option
  22. The MIDAS is a gas detector with an integrated sampling pump for exotic rare gases detection. It detects: AsH3, B2H6, BCl3, BF3, Br2, C2H4O, Cl2, ClF3, ClO2, CO, COCl2, F2, GeH4, H2, H2S, H2Se, HBr, HCl, HCN, HF, HMDS, N2H4, NH3, NO, NO2, O2, O3, PH3, POCl3, Si2H6, SiCl4, SiHCl3, SO2, TEOS, TMB, TMP, WF6.

    • Wide range of "rare" toxic gases detectable at low concentration levels
    • Integrated suction pump system: flow rate 500 ml/min
    • Pyrolysis module for fluorinated gases: C4F6, C5F8, CH3F, DCE 1.2, NF3, SF6
    • 3 configurable NO or NC alarm relays for control and 4-20 mA output
    • Ethernet (PoE) TCP/IP and Modbus communication
  23. The SearchPoint Optima Plus explosive gas detector has been specifically designed to detect hydrocarbons in certified potentially explosive atmospheres (ATEX). With a fast response time and a wide range of gases available, it is particularly suitable for offshore platforms, oil and gas terminals, refineries, etc.

    • IR technology with dual 4-beam source
    • Over 100 calibration curves available (hydrocarbons, solvents, alcohols)
    • Very short response time (T50 < 3 seconds - T90 < 4 seconds)
    • Worldwide ATEX, IECEx, UL, and CSA certifications and approvals
    • Very high reliability with an MTBF of over 28 years
  24. Available for the detection of hydrocarbons and carbon dioxide (CO2), the GD10P infrared gas detector sets the standard for gas detection on offshore drilling platforms. The detector's optomechanical design is so stable that it provides an exceptionally high response time and an exceptional service life.

    • Fixed gas detector with infrared technology: hydrocarbon vapours and CO2
    • Fast response time and exceptional lifetime (> 15 years)
    • Continuous self-test function: signals optical defects or malfunctions to the control system
    • No saturation effect: the detector can measure gas concentrations up to 100 % vol
    • Factory calibration, no on-site recalibration
  25. The OBSERVER-i is a third-generation ultrasonic gas leak detector for quick gas leak detection under pressure (from 2 bar). It is the first ultrasonic detector equipped with an artificial neural network (ANN) that uses patented technology to detect only gas leaks by suppressing unwanted background noise.

    • Quickly detects leaks of all gases under pressure (2bar)
    • Wide detection range while maintaining immunity to false alarms
    • Consistent detection coverage up to 28 metres away
    • Patented and proven Senssonic™ self-test function
    • A very cost-effective solution in the open air where conventional detectors are ineffective
  26. The Searchline® Excel detector is a linear gas detection barrier consisting of an infrared transmitter and a receiver that can be located up to 200 meters away. It is particularly suitable for methane, pentane, ethane, butane, propane, ethanol, ethylene, methanol, and propylene detection in petrochemicals and large-scale storage areas.

    • Highly accurate detection of hydrocarbons over distances of up to 200 meters
    • Fast response time with a T90 fewer than 3 seconds
    • Linear 4-20 mA and Modbus RS485 multidrop output
    • Simple installation and commissioning, one system replaces multiple point devices
    • Safety approvals: ATEX, IECEx, UL, CSA, FM, and GOST
  27. The SPM FLEX is an optical gas analyser combining the colour change of a chemically impregnated paper strip with a powerful optic analysis system. It is particularly suitable for the detection of mineral acids (HNO3, H2SO4), hydrides (H2Se, H2S, SiH4), amines (DMA, TD-MAT), and diisocyanates (TDI, MDI, HDI) at low concentrations (in ppb).

    • Detection of hydrides, mineral acids, oxidants, amines, diisocyanates, phosgene, hydrazines, hydrogen peroxide, etc.
    • Patented Chemcassette® technology: fast, highly accurate analysis method insensitive to interferences
    • Integrated gas sampling pump (up to 30 meters for some gases)
    • Digital display of target gas concentration in ppb (parts per billion)
    • Minimal maintenance with no need for calibration

Most of fixed gas detection systems for toxic and combustible gases feature a 4-20 mA linear output to connect to a gas detection controller and are ATEX compliant. A more advanced fixed gas detector can also be equipped with a digital display, alarm relays or digital communication. There is a specific sensor technology for each type of gas that ensures the accuracy and the frequency of measurements (Learn more about sensor technologies).

Combustible gas detector (explosimeter)

A combustible gas detector (natural gas, LPG, hydrocarbons, solvents, alcohols) stands for the largest part of gas detection. A fixed gas detector for combustible gas can be used in almost any sector: industries with SEVESO or COMAH sites, chemistry, petro chemistry and also in the tertiary sector with boiler rooms gas detection for example. There are two major monitoring technologies depending on the targeted combustible gas to detect :

  • Catalytic sensor: sensor technology used for almost every combustible gas. This solution is very efficient for natural gas, LPG, hydrocarbons, solvents and even some volatile compounds monitoring.
  • Infrared sensor: this technology should be preferred for every sector with a constant residual presence of combustible gases (refineries, paint or solvents plants, distilleries…).

Toxic gas detector

As the use and the manufacturing of highly toxic products in the industry is growing stronger, dangers to goods (risk of explosion) and to people (risk of poisoning) are growing as well. Throughout the world every day explosions and death occur and recall this problem.

The most commonly used sensor technology for monitoring toxic gases is the electrochemical sensor. This technology, that can be found in a portable or a fixed gas detector, provides a large panel of gas detection sensors. For some rare gases that require measurements expressed in ppb (parts per billion), only the colorimetric paper technology will be available for fixed gas detection.

Asphyxiant gas detector ( lack of oxygen)

Asphyxiating gases includes many gases with the same property: they reduce oxygen rate. Even if in almost any case an oxygen gas detector (O2 detector) is enough, it is recommended to use an asphyxiant gas detector when it is available such as a CO2 gas detector (carbon dioxide) or an helium fixed gas detector for example.

  • Electrochemical sensor for oxygen and some rare gases
  • Infrared absorption sensor for carbon dioxide (CO2)
  • Catalytic sensor for almost any combustible gas that can replace oxygen in case of leakage

VOC detector (Volatile Organic Compound)

Volatile organic compounds (VOC) are a wide family of gases and gaseous substances that can be pollutant, toxic and even carcinogenic. As they are volatile, they can easily spread into the atmosphere. That's why it is necessary to detect and measure them with a fixed VOC monitor to be protected.

Even if VOC can compose explosive mixtures, they are very toxic before their concentrations reach an explosive level (tens of thousands parts per million). Indeed, their level of explosiveness is set at tens of ppm. Several technologies for VOC detectors are available depending on the risk to monitor:

  • Photo-ionization lamp (PID lamp) or semi-conductor sensor for toxicity detection (expressed in ppm).
  • Catalytic sensor or infrared absorption sensor (when available) for explosiveness detection (expressed in % LEL).

Refrigerant gases detector (freons)

Halogenated hydrocarbons (CFCs and HCFCs), alkenes (HFOs) and almost any refrigerant gas are regulated under a particular legislation that limits (or forbids) their use. The use of refrigerants also requires a monitoring system – usually a fixed gas detector for freons. There are two main measuring technologies for freons:

  • Semi-conductor sensor: the most commonly used technology for freons monitoring
  • Infrared absorption sensor: a very accurate but very expensive technology used for some freons

GazDetect offers, on specific territories, many services for fixed gas detection like on-site installation, setup, commissioning and calibration of gas detectors. We can also perform maintenance and periodical checkings of your fixed systems. (go to the Maintenance and on-site calibration section)